/* 引入依赖的模块 */
var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');

/* 引入路由模块 */
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');

/* 创建 Express 应用实例 */
var app = express();

/* 设置使用到的视图模板引擎 */
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');

/* 使用中间件 */
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());

/* 指明静态资源所保存的位置 */
app.use(express.static(path.join(__dirname, 'public')));
/* 使用路由中间件 */
app.use('/', indexRouter); // 表示访问 '/' 下的资源，到 indexRouter 对应的路由中处理
app.use('/api/users', usersRouter); // 表示访问 '/api/users/' 目录下的资源

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;
